When can we stop using the term "digital cameras" and just call these things "cameras"? They began outselling film-based cameras in 2003, and by the end of this year over half of U.S. households will own a digital model, according to the Photo Marketing Association International.
But their mass-market status doesn't change the fact that digital cameras remain computers with lenses, and they require some of the same careful shopping -- from contemplating puzzling measurements to choosing among incompatible formats.
Where the big number in computers is processor speed, in digital cameras it's megapixels -- millions of picture elements of resolution. And it's almost as easy to go overboard on resolution as on processor speed.
You need at least three megapixels, which will allow good 4-by-6 prints and uncropped 8-by-10 blowups. Stepping up to four megapixels increases your odds of getting a quality 8-by-10; five adds the option of still larger blowups. But don't buy more than that unless you crop your photos with an ax instead of a scalpel or routinely order massive blowups; the larger files generated by six- or seven-megapixel cameras will only fill up your storage card faster and slow down transfers of pictures to a computer.
(Camera phones max out at two megapixels, and most offer far less resolution. They can't replace a stand-alone digicam, although they are supremely convenient for taking and sending random pictures on the go -- for example, the "Honey, does this chair look nice to you?" photo e-mailed from the mall.)
The lens in front of a camera's image sensor is the other important thing to consider. Pay attention to optical zoom numbers, not digital zoom. Most cameras include at least a 3X zoom, and some go up to 5X; going beyond that generally requires buying a bulkier model with a protruding lens that won't fit in a pocket or purse.
That, in turn, undercuts one of the primary advantages of digital cameras -- the ability to take one to as many places as possible. That's also why I don't recommend D-SLRs -- "digital single-lens reflex" models that, like their film equivalents, let you frame a shot through the same lens used by the image sensor. They take extremely sharp pictures and do so extremely quickly, but they also cost far more and are hardly smaller than film SLRs. Hold off on any D-SLR shopping until you find you're making photography a serious hobby.
Getting a smaller camera doesn't have to mean giving up on picture quality, thanks to effective miniaturization of things like image sensors and lenses. (See Alan Kay's story on Page F7 for more on the trade-offs between compact and subcompact cameras.) It can, however, mean giving up on the convenience of using standard AA batteries for the slimmer shapes of proprietary rechargeables.
That's not necessarily bad -- if you're disciplined enough to remember to recharge your camera's battery and take its charger, or a spare, on trips. With a camera that accepts AAs, however, a recharge is never farther away than the nearest convenience store. Just remember to invest upfront in a set of rechargeable AAs, or you'll be throwing money away at a brisk pace with each exhausted set of batteries pitched in the trash.
With analog cameras, film is film, but with digital cameras you need to choose between different, incompatible types of removable memory. So far, seven major types have been put on the market -- floppy disks, recordable CDs, Compact Flash cards, Memory Sticks (which themselves come in two shapes), SmartMedia cards, SD Cards, and xD-Picture Cards -- and only one has disappeared (the SmartMedia).
SD Cards have the advantage of compact size, low cost and wide support -- you can find SD Card slots in most desktops, many laptops and almost all handheld organizers. Compact Flash cards can cost a little less and come in larger sizes, up to eight gigabytes. None of the other formats offers any particular value -- Memory Sticks and xD cards cost more, sometimes twice as much as SD or CF cards of the same size, while floppy disks and rewriteable CDs add too much bulk to digital cameras.
Since the "starter" cards bundled with new cameras offer as little as 16 megabytes of memory, you'll need to add the cost of another card, preferably 512 MB, to your digital-photography budget.
Some digicams supplement storage cards with built-in memory. That sounds convenient but is not: Given how many computers feature memory-card slots, it's far more convenient to pop the card into the computer than to find the camera's proprietary USB cable.
While digital cameras keep getting smaller, the color displays on their backs -- used to frame shots and inspect recently taken photos -- have started getting bigger. That's a welcome trend, since it's much easier to spot flaws in a picture on an LCD larger than an airmail stamp. But in some cases, the bigger screen comes at the sacrifice of a regular optical viewfinder, the glass window that allows you to shoot without turning on a battery-draining display.
Camera vendors usually talk up the extras of movie modes and bundled software, but neither is worth your attention. Unless you get an enormous storage card, you won't be able to record more than a few minutes of video, and the included photo-album programs usually fall short of such competitors as Apple's iPhoto and Google's Picasa.
What is worth consideration is the level of automation in a particular camera. If you're used to point-and-shoot film cameras, you can find the same convenience in most digital cameras, sometimes augmented by a set of pre-programmed shooting modes accessible with the twist of a dial. Users who like to balance shutter and aperture settings on their own, however, will need to do some shopping to find models with those features.
It's not a good idea to spend too much on any one digital camera because of the one way that digital cameras still fall short of film models: They become obsolete as image sensors keep getting smarter, faster and smaller. That's probably not going to change for a while, not while 50 percent or so of the market has yet to be persuaded to buy a digital camera.
Living with technology, or trying to? E-mail Rob Pegoraro at email@example.com.